Piston and metallic packing therefor.



No. 793,973 PATENTED JULY 4, 1905.

- r E. T. WHITE.

PISTON AND METALLIC PACKING THEREFOR.

PPPPP OLTIOH FILED APR. 5, 1905.

.. kg i.

NITED STATES.

Patented. July 4, 1905.

" ATENT FFICE.

PISTON AND IVIETALLlC PACKING THEREF OR.

SPECIFICATION forming part of Letters Patent No. 793,97 3, dated July 4,1905,

Application filed April 5, 1905. Serial No- 253,946.

cessive frictional pressure of the ring against the cylinder.

It is desirable to use packing-rings of sufli- .cient width andthickness to prevent breakage of the rings; but in increasing the widthof the ringthe frictional contact and wear on the cylinder isproportionately increased and a greater proportion of the powerdeveloped in the cylinder is absorbed by this frictional resistance.

By my invention I employ a packing-ring of increased width withoutincreasing the fric-- tional resistance, because 1 partially equalize orbalance the pressureon both sides of the.

. ring, and a tight packing in the cylinder, with a minimumfrictionalresistance, thereby reducing the rapid wear on cylinders thattakes place on packing where high steam-pressures are used, and thusprolonging the life of both the cylinder and the packing and permittingthe power now absorbed in the cylinder by this frictional resistance tobe utilized in increasing the work done by the engine.

The accompanying drawings illustrate the invention, in which. I

Figu-rel shows a sectional view of portions. of a cylinder provided witha piston having my improved features. Fig. Qillustrates a front.elevation of the piston and a. sectional View of the cylinder inclosingit. Fig. 3 is a detail sectional view, on an enlarged scale, of

aportion of the piston and packing-rings; and Figs. 4 and 5 illustratemodified forms of de-.'

vices.

Referring to the drawings, Figs. 1, 2, and 3, the numeral 1 designatesthe cylinder, 2 the. piston, and 3 the piston-stem. The piston head isprovided with one or more annular or circumferential channels, and atthe base openings or passages which extend from the side to the annularchannels. A metallic packing-ring 9 is fitted in each of thecircumferential channels, and said rings are provided at opposite edgesof their outer contact-faces with outwardly-projecting contact-flanges10, and also on the outer faces the rings are provided with a centralannular steam-space 11.

A plural number of ports 12 are also provided I in the ring, and saidports extend radially through the center of the rings from thesteam-space 11 at the outer side of the ring to the contracted space 13,formed between the shoulders 5 at the inner side of the rings and in aplane coincident with the ports 8 in the piston-head. It will'thus beseen that a steam-space is provided on opposite sides of thepacking-rings and that the ports 12 establish communication between saidsteamspaces.

Referring to Fig. 4, it will be seen that the invention is readilysusceptible of modification by providing the inner side of the ringswith shoulders 14 instead of the shoulders 5 in the channels 4: of thehead, and by reference to Fig. 5 another modification is illustrated, inthat the piston-head 15 has no side ports? and lateral ports 8, in whichcase the steam that would ordinarily pass around the ring will act onopposite sides of the latter, and thus reduce the frictional contactbetween the rings and cylinder.

It is to be understood that in practice the steam will pass through theside ports 7 of the piston-head, then through lateral ports 8 into thereduced or contracted steam-space 13 at the inner side of the ring, thenthrough the ports 12 in the rings to the outer central steamspace 11between the two side flanges 10. By

this arrangement steam-pressure is applied to the rings at oppositesides, so that the pressure at the outer side of the rings will cou n'teract to a considerable degree the pressure on the inner'side, and thusreduce the excessive contact-pressure of the ring against the cylinder.

Having thus fully described myinvention, what I claim as new, and desireto secure by Letters Patent, is-

I steam-space, 11; mechanical means for keeping the said ring spacedfrom the bottom of the channel to form" on the inner side of the ring asteam-space, 13, and ports through the ring to establish communicationbetween said exterior and inner annular spaces, whereby a packing-ringof maximum width may be em ployed without increase of frictionalresistance'of the ring against the cylinder.

, 2. A piston-head having a circumferential channel and ports leadingfrom the side of the i head and opening into said channel, said ringhaving an exteriorflange at each side and an annular exteriorstear'nspace between said side flanges and also having one-or more portsextending from the central exterior annular steam-space to the innerside of the ring.

3. A piston-head having a circumferential channel with annular shouldersin said 'channel and ports leading from said channel to the side of thehead, a packing-ring fitting in said channel and having an annularexterior central steam-space with a flange at each side thereof and alsohaving ports leading from said exterior steam-space to the inner sideofthe ring. I ,y

In testimony whereof Iaffix my signature in presence of two witnesses.

EBENEZER T. WHITE. Witnesses: CHARLES B. MANN, J r.,

FELIX R. SULLIVAN.

